Device for removing needles from a fabric web

ABSTRACT

At the outlet end (B) of a tentering frame ( 1 ), on the side of the tentering frame chains with needle plates ( 3 ) there are transport means ( 11 ) in the shape of conveyor belts ( 19 ) and clamping bands ( 23 ), whose runs ( 19′, 23 ′) intersect the plane (E) formed by the tentering frame chains ( 3 ) at an acute angle (alpha) at a point (X). The needles are removed from the fabric web ( 39 ) which is guided in a clamped way during the needle removal by the conveyor belts ( 19 ) and clamping bands ( 23 ).

BACKGROUND

The object of the invention is a device for removing needles from a fabric web carried on a tentering frame, with two tentering frame chains, which carry the fabric web by its longitudinal edges and which transport and hold the fabric web in tension perpendicular to a transport direction between a web receiving point and a web outlet point.

For processing textile webs, especially knitted, double-ribbed, as well as stitched textiles, and also for nonwoven fabrics, the fabric web is fixed along its longitudinal edges by needles on a tentering frame. At the end of the tentering frame, the fabric web must be removed as carefully as possible from the needle setting, which is typically embodied on circular transport bands. The removal can be achieved by wedge-shaped rails, which lie at an acute angle to the fabric web, which extend parallel to the needled bands, and which successively lift the fabric web from the needle setting. In a tentering frame at the end of the run of the material web, because the latter is usually held in tension between the needles, removing the needles can damage the edges of the material web, as soon as the web is no longer completely held by the penetrating needles.

SUMMARY

An object of the present invention is to create a device for removing needles from a fabric web, in which the fabric web is not damaged by the needles when the needles are removed.

This objective is achieved by a device according to the features of the invention, in which at the web outlet point at the side of the tentering frame chains there is at least one conveyor belt having a first segment intersects the transport plane of the tentering frame chains at an angle.

With the device according to the invention, the fabric web is held in a controlled way during the needle removal and, as much as desired, also afterwards. The tensile forces acting from the fabric web perpendicular to the transport direction can be temporarily assumed by the device during the needle removal. The device further enables a controlled transition to the subsequent transport means, whether it is a transport belt running at the same speed or a transport belt at a lower speed in order to flatten the fabric web and to give the web the opportunity to shrink (relax).

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail with reference to an illustrated embodiment. Shown are:

FIG. 1 is a view of a tentering frame with diverging needled bands,

FIG. 2 is a longitudinal section view along line II-II in FIG. 1 through the device, and

FIG. 3 is an enlarged cut-out of the longitudinal section in FIG. 2 in the transfer/transition region.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1, illustrated by a trapezoid, a tentering frame 1 with two tentering frame chains with needle plates 3 designed for the web transport can be seen. The tentering frame chains with needle plates 3 run endlessly around guide rollers 5, 7 and are driven by a motor M. Between the guide rollers 5, 7, the upper ends of the tentering frame chains 3 are supported on sliding surfaces 9. The two tentering frame chains 3 diverge in the illustrated example. Consequently, on the inlet side at the web receiving point A, the two tentering frame chains 3 lie closer to each other than at the web outlet point B. The formation of the tentering frame 1, as shown schematically in the drawings, is not described in more detail, as it is known from the state of the art.

In the region of the web outlet point B, corresponding transport means 11 are arranged between the two tentering frame chains 3 directly adjacent to each chain. The two transport means 11 can be arranged parallel to the adjacent tentering frame chains 3 or they can enclose an acute angle beta with these chains. The transport means are preferably endless conveyor belts or pulleys 19 rotating around at least two guide rollers 13, 15. A deflection roller 17, which divides the upper run of the conveyor belt 19 rotating on the guide rollers 13, 15 into two segments 19′ and 19″, is preferably inserted between the two guide rollers 13, 15. The lower run 19′″ can likewise be deflected upwards by a support roller 21 as much as necessary for structural reasons. The conveyor belts 19 can be driven by a motor (not shown), preferably a servo motor. An endless clamping band 23 runs over each conveyor belt 19 over at least two guide rollers 25, 27. Their lower runs 23′ contact both the segment 19′ and also the segment 19″ and in this way they are deflected. The upper run 23′ can be lifted by a deflection roller 29, if necessary.

Alternatively, at the point where conveyor belts are deflected by deflection rollers, conveyor belts, which are offset relative to each other and which have a segment that assumes the desired angle, can be used.

At the position x, the upper run 19′ of the transport belt 19 intersects the plane E, in which the upper segments of the tentering frame chains 3 run at an acute angle alpha in the illustrated example. The intersecting angle between the plane E and the upper run 19′ can equal up to 90°.

The transport means 11, including the transport belt 19 and the clamping belt 23, extend past the web transfer region A and also extend past a conveyor system 33 cooperating with the tentering frame 1. This system can be a band, lattice, or screen 37, which extends around the guide rollers 35 and on which a fabric web 39 passing through the tentering frame 1 is carried away.

In the following, the method of operation of the device is explained in more detail. In the figures, the fabric web 39 is guided from the left in a known way to the tentering frame 1 and connected to the tentering frame chains 3 along its edges. The material web 39 in the example of a divergent tentering frame 1 is successively pulled apart perpendicular to the transport direction T by the two tentering frame chains 3, which are driven in sync. Shortly before reaching the web outlet point B, the edge regions of the fabric web 39 are brought into contact with the transport bands 19 of the transport means 11. Due to the segment 19′ of the transport bands 19 running upwards at the acute angle alpha, the edges of the fabric web 39 are successively lifted and led out of the needles of the tentering frame chains 3 and thus the connection to the needle bands 3 is broken. During the run-out of the web edges, the fabric web 39 is pressed by the lower run 23′ of the clamping band 23 to the segment 19′ of the transport band 19 and thus held or clamped tight. The clamping of the fabric web 39 during the needle removal cancels the tensile forces, which have been generated by the expansion of the fabric web 39 in the tentering frame 1 and prevents the needles from pulling threads out of the surface of the lower side of the fabric web 39.

The guidance of the conveyor belts 19 and clamping bands 23 at an acute angle beta to the transport direction of the tentering frame chains 3 has proven to be especially advantageous. Through these measures, the fabric web 39 is stretched further perpendicular to the transport direction T by the mentioned bands during the needle removal and thus the tensile forces on the needles at the tentering frame chains 3 are completely canceled.

The controlled needle removal of the web 39 from the tentering frame 1 enables the released web 39 to be deposited on a subsequent conveyor system 33, whose conveyor speed v₂, e.g., can be less than the conveyor speed v₁ of the tentering frame chains 3 in order to give the material web 39 the opportunity to shrink/relax. The conveyor speed of the conveyor band 19 and the clamping band 23 can likewise be different with reference to the speed v₁ of the tentering frame chains 3 in order to aid the needle removal. 

1. Device for removing needles from a fabric web (39) in a tentering frame (1), comprising two tentering frame chains (3), which carry the fabric web (39) on longitudinal edges thereof and which transport and hold the fabric web (39) in tension perpendicular to a transport direction (T) between a web receiving point (A) and a web outlet point (B), at the web outlet point (B) at a side of the tentering frame chains (3) there is at least one conveyor belt (19) having a first segment (19′) that intersects the transport plane (E) of the tentering frame chains (3) at an angle (alpha).
 2. Device according to claim 1, wherein a second segment (19″) of the at least one conveyor belt (19) lies at an acute angle to the first segment (19′) and extends past the web outlet point (B).
 3. Device according to claim 1, wherein over the at least one conveyor belt (19) there is a clamping band (23) having a lower run (23′) that lies opposite the first segment (19′) of the conveyor belt (19), which forms an upper run.
 4. Device according to claim 1, wherein there are at least two of the conveyor belts (19) that are arranged at an acute angle (beta) to the tentering frame chains (3).
 5. Device according to claim 1, wherein the tentering frame chains (3) and the at least one conveyor belt (19) can be driven independently and at the same and different speeds. 